A regional geological survey background map service application method based on survey coordinate system

Abstract

A method for applying a regional geological survey background base map service based on a survey coordinate system comprises the following steps: S1: base map data storage; S2: base map data service release; based on Gauss-Kriging projection, the base map file is segmented into multiple levels according to different tile levels and then data is released; the steps include: obtaining the Gauss-Kriging projection coordinate range, confirming the coordinate origin, and constructing a level 0 square slice with the longest side in the map sheet as the side length; starting from the level 1 square slice, slices of each level are generated on the basis of the previous level square slice according to the principle of quartering; S3: base map service application; including: monitoring service requests, calculating tile levels and ranges, and retrieving corresponding tiles for return; the present invention segments the base map data according to the map sheet based on the Gauss-Kriging projection coordinates, realizes hierarchical tile release, improves the efficiency and stability of base map release, and can meet the actual needs of field geologists in carrying out geological survey work according to the map sheet.

Description

Technical Field

[0001] The present invention relates to the field of geological survey information application and service technology, and more specifically to a regional geological survey background base map service application method based on a survey coordinate system. Background Art

[0002] The background base map data for regional geological surveys include publicly released aerial or satellite image data that meet accuracy requirements, geographic element vector data, and vector graphics of comprehensive results formed by previous research. The content is characterized by strong macroscopicity, realistic images, and rich information, providing the most intuitive base map basis for field geologists.

[0003] The geological survey intelligent space is a business working environment provided to geological workers during the current national geological survey work, which can cover geological survey data collection, transmission, aggregation, comprehensive analysis and processing, modeling, evaluation and prediction, data mining and knowledge discovery. Its important service capabilities include platform-level services, data services, knowledge services, tool services, etc. Therefore, in the process of regional geological survey projects, the demand for background base map data to be provided to field geologists in the form of services is becoming more and more widespread.

[0004] At present, when images or vector data used by various industries are used as online tile data services, the common situation is that they are WEB Mercator projection or geographic coordinate system (latitude and longitude). However, regional geological surveys are mainly based on the international standard map sheet of 1:50,000 or 1:250,000 for work deployment. In order to meet the accuracy requirements of the survey, the coordinate projection method of the background map requires the use of Gauss-Kriging projection; if the background map of Gauss-Kriging projection is published as an online tile data service based on WEB Mercator projection or geographic coordinate system (latitude and longitude), it will not only increase the workload of data projection transformation processing, but also make it difficult to meet the actual call and visualization requirements of field data collection work.

[0005] On the other hand, due to the large volume and variety of base map file data, if a single database is used for storage, it will not be possible to quickly retrieve the current local geological survey background data and perform correlation analysis with business data.

[0006] Therefore, it is an urgent problem for technical personnel in this field to realize the publishing and service application of background base map data that can fully meet the measurement coordinate system requirements of regional geological surveys and at the same time have high efficiency and high stability. Summary of the invention

[0007] In view of this, the present invention provides a method for applying a regional geological survey background map service based on a measurement coordinate system, which solves the problem that conventional WEB Mercator projection or geographic coordinate system (latitude and longitude) online map services cannot fully meet the requirements of regional geological survey background map projection methods, and also ensures the high efficiency and high stability of background map service publishing and application.

[0008] In order to achieve the above object, the present invention adopts the following technical solution:

[0009] A method for applying a regional geological survey background map service based on a survey coordinate system comprises the following steps:

[0010] S1: base map data storage;

[0011] S2: Basemap data service release; including:

[0012] Extract the base map file to be published from the database;

[0013] Based on Gauss-Kriging projection, the base map file is split into multiple levels according to different tile levels and then the data is released;

[0014] The segmentation step includes: obtaining the Gauss-Kriging projection coordinate range of the map sheet according to the map sheet number, confirming the coordinate origin, and constructing a level 0 square slice with the longest side in the map sheet as the side length; starting from the level 1 square slice, generating slices of various levels based on the square slice of the previous level according to the principle of quartering;

[0015] S3: Basemap data service application; including:

[0016] Listen to service requests, calculate tile levels and ranges, and retrieve corresponding tiles for return.

[0017] Preferably, the S1 specifically includes:

[0018] Extract the map metadata file and image metadata file based on the uploaded base map file;

[0019] Extracting associated information from the map metadata file and the image metadata file;

[0020] The extracted associated information and base map files are stored in the corresponding databases respectively.

[0021] Preferably, the S1 step further includes:

[0022] Data asynchronous processing: confirm the data source storage address, call the base map file storage interface, push the message to the storage message queue, and use the message queue monitoring method to perform asynchronous processing;

[0023] Data verification and identification: According to the data source storage address, check whether there is a file under the address; if there is a file, traverse the map data folder, identify the data file type according to the file name, and classify the data.

[0024] Preferably, the base map file is stored in a MinIO database, and the associated information is stored in a PostgreSQL database.

[0025] Preferably, S2 includes:

[0026] According to the associated information, the storage location information of the corresponding base map file is extracted from the PostgreSQL database, and according to the storage location information of the base map file, the base map file to be published is extracted from MinIO.

[0027] Preferably, S2 includes: before segmentation, traversing the base map files in the map data folder to determine the data type thereof;

[0028] If it is shp data, the coordinate origin and other information are extracted according to the map sheet number, and then the shp data is segmented; if it is DGSS vector data, the coordinate origin and other information are extracted according to the map sheet number, and the vector data is converted into MapGIS data format, and then the vector data is segmented; if it is image data, the coordinate origin and other information are extracted according to the map sheet number, and then the image data is segmented.

[0029] Preferably, S2 includes: after the segmentation is completed, calling the corresponding data publishing interface to publish the data according to the data type, and judging whether the publishing is successful;

[0030] If the release is successful, the data is traversed to obtain the published tile URL address and the base64 data stream of the tile, and the data preview information is stored in PostgreSQL. At the same time, the data release status of the file directory information and metadata information associated with the data release is updated, and finally the data release log is recorded; then the corresponding tile can be viewed on the WEB browser through the tile URL address.

[0031] If the release is not successful, the data release log is recorded directly.

[0032] Preferably, S3 includes:

[0033] Obtain basic information, including the scale, origin coordinates and map sheet number of the current base map;

[0034] Calculate the map range according to the map number, calculate the tile level according to the display ratio of the map view window, and calculate the tile row and column number range based on the Gauss-Kriging projection coordinate range; organize the tile row and column number range and level according to the service established format, and initiate a tile download request;

[0035] Get the tile data returned by the download request and visualize it on the mobile terminal.

[0036] Through the above technical solution, it can be known that compared with the prior art, the present invention discloses a regional geological survey background base map service application method based on a measurement coordinate system. Aiming at the problem that the currently commonly used online tile data service cannot fully meet the requirements of the regional geological survey background base map projection method, in the base map data segmentation process, according to the international standard map segmentation requirements of the current regional geological survey work, based on the Gauss-Kriging projection, segmentation is performed according to unified rules to fully meet the actual needs of business development; at the same time, it avoids the situation where a single database is used for base map data storage and cannot support its fast service and fusion application with other business data. By using a hybrid database to store the original base map file, the storage location information of the file and the related information in the background, the service release mechanism is triggered after uploading the data in the background, thereby improving the efficiency and stability of base map service release and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0038] Figure 1 A schematic diagram of a regional geological survey background map service application method based on a survey coordinate system provided by the present invention;

[0039] Figure 2 A schematic diagram of a base map data storage method in an embodiment of the present invention;

[0040] Figure 3 The base map data file storage organization chart in the embodiment of the present invention;

[0041] Figure 4 Schematic diagram of a method for publishing base map data in an embodiment of the present invention;

[0042] Figure 5 is a schematic diagram of a level 0 image slice in an embodiment of the present invention;

[0043] Figure 6 is a schematic diagram of a level 1 image slice in an embodiment of the present invention;

[0044] Figure 7 A flowchart of base map data service acquisition in an embodiment of the present invention;

[0045] Figure 8This is a flowchart of the base map data service application rendering in an embodiment of the present invention. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] like Figure 1 The embodiment of the present invention discloses a regional geological survey background map service application method based on a measurement coordinate system, comprising the following steps:

[0048] A method for applying a regional geological survey background map service based on a survey coordinate system, characterized in that it comprises the following steps:

[0049] S1: Basemap data storage.

[0050] S2: Base map data service release; including: extracting the base map file to be released from the database; based on the Gauss-Kriging projection, splitting the base map file into multiple levels according to different tile levels and then releasing the data; wherein the splitting step includes: obtaining the Gauss-Kriging projection coordinate range of the map according to the map sheet number, confirming the coordinate origin, and constructing a level 0 square slice with the longest side in the map sheet as the side length; starting from the level 1 square slice, generating slices of various levels based on the square slice of the previous level according to the principle of quartering; and publishing the splitting results.

[0051] S3: Base map data service application; including: listening to service requests, calculating tile levels and ranges, and retrieving corresponding tiles for return.

[0052] In one embodiment, if Figure 2 , S1 specifically includes:

[0053] S11: Asynchronous data processing: Select the base map data source storage address, call the base map file storage interface, and push messages to the base map data storage message queue for large base map file data volumes, and use the message queue monitoring method for asynchronous processing. Among them, the base map file is copied by the system administrator in batches to the designated data directory of the server; or a system user uploads data to the designated data directory of the server through the client.

[0054] S12: Data verification and identification: According to the base map data source storage address, check whether there is a file under the address, for example, whether there is a frame vector file under the frame directory folder, and whether there is a specific image file under the image data directory folder; if the file exists, traverse all map sheet number folders, identify the data file type according to the file name, and classify the data.

[0055] S13: Metadata parsing: Parsing map metadata and image metadata; There is a map metadata directory under each map number folder. This directory contains a metadata description XML file, which mainly stores some information about the map. In each specific image data folder, in addition to the image file itself, there is also an XML file describing the image metadata. Parsing metadata is to read information from the XML file.

[0056] Among them, the map metadata specifies the basic requirements and content of metadata. These metadata contents include but are not limited to the identification information, spatial reference information, production information, quality information and distribution information of the dataset. Image metadata refers to the attributes of the image itself, such as image resolution, band information, acquisition time, geographic coordinates, etc. Image metadata can help users understand and use image data, and ensure that image data can be correctly identified and processed in different applications.

[0057] S14: File information extraction: based on the metadata analysis results, extract file directory information, file basic information, file storage location information, related information, etc.;

[0058] S15: Data storage: including the storage of base map files and the storage location information and related information of the files. The specific storage steps are:

[0059] S151: Store the base map data file in MinIO, organize the data by scale-map number, and divide it into satellite image data, geographic element vector data, comprehensive results vector data, and map metadata. Among them, the subtype and directory of satellite image data are not fixed, and users design them according to actual needs; geographic element vector data are divided into geographic element layers (shp format) and frames (DGSGIS format); comprehensive results vector data include remote sensing interpretation maps, geological and mineral maps, and other comprehensive analysis spatial data formed by previous research (shp format, MapGIS format, DGSGIS format); map metadata is an XML file that comprehensively describes the map data information; its storage organization structure is as follows Figure 3 shown.

[0060] S152: Storing the storage location information and associated information of the extracted base map file in the PostgreSQL database.

[0061] In this embodiment, MinIO is a high-performance distributed object storage service, which is particularly suitable for storing large amounts of unstructured data, such as photos, videos, log files, etc.; PostgreSQL is an open source object-relational database management system that supports a variety of application scenarios, including WEB applications, data warehouses, embedded databases, etc., and can handle complex queries and provide a high level of data integrity.

[0062] In one embodiment, if Figure 4 , S2 specifically includes:

[0063] S21: Asynchronous data processing. Select the base map data to be published, call the base map data publishing interface, push the message to the base map data publishing message queue, and use the message queue monitoring method for asynchronous processing.

[0064] S22: Respond to the request in the message queue to extract the basemap file. Initiate a query based on the relevant information of the target basemap data, such as data ID or batch; the relevant information is stored in the PostgreSQL database in the form of associated information when stored in S1; extract the storage location information of the corresponding basemap file from the PostgreSQL database based on the selected basemap data batch information / data ID number to be published, and then extract the associated basemap file to be published from MinIO based on the storage location information of the basemap file.

[0065] S23: Identify the file type of the base map file to be published, and segment the base map data.

[0066] S231: If it is shp or MapGIS data, the coordinate origin and other information are extracted according to the map sheet number, and then the shp or MapGIS data is segmented; if it is DGSGIS data, the coordinate origin and other information are extracted according to the map sheet number, and the vector data is converted into MapGIS data format, and then the vector data is segmented; if it is image data, the coordinate origin and other information are extracted according to the map sheet number, and then the image data is segmented.

[0067] S232: Slicing. Obtain the Gauss-Kriging projection coordinate range of the map sheet according to the map sheet number, confirm the coordinate origin, and construct a level 0 square slice with the longest side in the map sheet as the side length; starting from the level 1 square slice, generate slices of each level based on the square slice of the previous level according to the principle of quartering. Next, take the image base map slicing of a certain map sheet as an example.

[0068] The Gauss-Kriging projection coordinate range of the map is: XMin: 194847.92258395004, XMax: 207759.92258395004; YMin: 2667513.0355180129; YMax: 2677019.0355180129.

[0069] For the above map, the calculation method of the actual spatial length of the 0th level image slice is:

[0070] Max{(XMax-XMin)|((YMax-YMin))}=12912;

[0071] The actual spatial range of the level 0 image slice is as follows: Figure 5 :

[0072] XMin:194847.92258395004;

[0073] The level 0 image slice is divided into four equal parts to obtain the level 1 image slice, which consists of four tiles with row and column numbers (0,0), (0,1), (1,0) and (1,1), as shown in Figure 6 .

[0074] The calculation of row and column numbers of spatial points at the Nth level and the inverse calculation of spatial range from row and column numbers can be performed by quartering based on the principle of the first level.

[0075] Based on the above data segmentation rules, the relevant calculation formula for the online map under a single map sheet can be obtained:

[0076] 1) The actual spatial length of the 0th level slice is calculated as follows:

[0077] Width=Max{(XMax-XMin)|((YMax-YMin))}

[0078] Among them, XMax, XMin, YMax, and YMin are Gauss-Kriging projection coordinates of the outer rectangular range of a single map sheet base map calculated by the map sheet number;

[0079] 2) The formula for converting row and column numbers of Gauss-Kriging projection coordinates is derived:

[0080] M=(GaussX-XMin)÷(Width÷2^Level)

[0081] N=(YMax-GaussY)÷(Width÷2^Level)

[0082] M and N represent the row and column numbers of the conversion respectively; GaussX represents the plane rectangular horizontal coordinate of any point on the tile after segmentation under the Gauss-Kriging projection; GaussY: the plane rectangular vertical coordinate of any point on the tile after segmentation under the Gauss-Kriging projection; Level: the slice level, starting from 0;

[0083] 3) The formula for back-calculating the tile Gauss-Kriging projection coordinate range based on the row and column numbers is:

[0084] TileMinX=M*(Width÷2^Level)+XMin

[0085] TileMaxX=(M+1)*(Width÷2^Level)+XMin

[0086] TileMinY=YMax-(N+1)*(Width÷2^Level)

[0087] TileMaxY=YMax-N*(Width÷2^Level).

[0088] Among them, TileMinX, TileMinY, TileMaxX, and TileMaxY are the Gauss-Kriging projection coordinate ranges of any tile after segmentation.

[0089] S24: Base map data publishing: according to the identified data type, the corresponding data publishing interface is called to publish the data and determine whether the publishing is successful.

[0090] If the release is successful, the data is traversed to obtain the published tile URL address and the base64 data stream of the tile, and the data preview information is stored in PostgreSQL. At the same time, the data release status of the file directory information and metadata information associated with the data release is updated, and finally the data release log is recorded; if the release is not successful, the data release log is directly recorded.

[0091] In one embodiment, S3 specifically includes:

[0092] S31: Base map data service acquisition process, such as Figure 7. For service requests initiated by the client, such as map metadata information, image metadata information or data download requests, the F5 load and domain name are mapped to the corresponding nginx proxy server, and the service gateway is used for identity authentication and data authentication, and the corresponding business service interface is called to obtain the corresponding service information from the database and return it to the client, realizing the mapping of data services from the intranet to the extranet. Users browse, download, search and other operations based on the information returned by the client. When users download basemap data, the corresponding files will be obtained from MinIO according to the user's selection and provided to the user for download.

[0093] S32: Base map data service application rendering process, such as Figure 8 .

[0094] S321: Listen to the base map service request and obtain the basic service information, including the origin coordinates (originX, originY) of the base map segmentation, the tile size (tileSize), the actual unit size (resolution) represented by a screen pixel at each level, and other information. The user's zooming, dragging, and other operations on the mobile terminal will change the basic information of the requested service. Combined with the map sheet number, and based on the screen distance and actual distance, determine the display scale, coordinate system, and other information of the current base map. Then obtain the coordinates of the lower left and upper right corners of the screen, convert them to the actual coordinate range, and perform a projection transformation to obtain the Gauss-Kriging projection coordinate range.

[0095] S322: Calculate the tile row and column number range according to the Gauss-Kriging projection coordinate range of the map view window. First, calculate the actual length of a tile, then calculate the actual distance between the base map coordinate point on the screen and the coordinate origin of the base map segmentation, and finally divide the actual distance by the actual length of a tile to obtain the tile row and column number at this time. The formula for calculating the tile row and column number where the coordinate point (x, y) is located is:

[0096] TileX=floor(originX-x) / (tileSize*resolution)

[0097] TileY=floor(originY-y) / (tileSize*resolution)

[0098] Among them, the origin coordinates (originX, originY) of the base map data segmentation, the tile size information tileSize of the base map (such as: 256*256 or 512*512, etc.), and the resolution information resolution corresponding to each Level level are obtained from S321.

[0099] S323: Arrange the tile row and column numbers (TileX, TileY), levels (level) and map sheet numbers into a service request address according to the service established format, and initiate a download request for tiles at the corresponding Level layer.

[0100] S324: Service data acquisition and visualization. Obtain the tile data returned by the download request in S323, calculate the Gauss-Kriging coordinate range of the tile according to the row and column numbers in S232 by inversely calculating the Gauss-Kriging projection coordinate range formula of the tile, render it within the specified range of the map view, and realize its visualization on the mobile terminal.

[0101] Repeat the processes of S323 and S324 to obtain and visualize all tiles within the entire map view range.

[0102] The present invention provides a method of using a hybrid database to store base map data in a fixed position of a server, wherein the original base map file is stored in MinIO, the storage location information and associated information of the base map file are stored in a relational database PostgreSQL, and a service publishing mechanism is triggered after uploading data in the background, and the base map data is segmented and published as a service by batch or item, thereby improving the efficiency of high-precision base map publishing, realizing fast base map service and supporting the integrated application with other business data. In the base map data segmentation process, according to the international standard map segmentation requirements of current geological survey work, based on Gauss-Kriging projection, segmentation is performed according to unified rules to fully meet the actual needs of business development.

[0103] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0104] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A regional geological survey background map service application method based on a survey coordinate system, characterized in that: The following steps are involved: S1: base map data storage; S2: Basemap data service release; including: Extract the base map file to be published from the database; Based on Gauss-Kriging projection, the base map file is split into multiple levels according to different tile levels and then the data is released; The segmentation steps include: obtaining the Gauss-Kriging projection coordinate range of the map sheet according to the map sheet number, confirming the coordinate origin, and constructing a level 0 square slice with the longest side in the map sheet as the side length; starting from the level 1 square slice, generating slices of various levels based on the previous level square slice according to the principle of quartering; S3: Basemap data service application; including: Receive the service request initiated by the client, and after identity authentication and data authentication through the service gateway, call the corresponding business server interface to obtain the corresponding service information and return it to the client; Obtain basic information, including the scale, origin coordinates, map sheet number and resolution information of the current base map; Confirming that the map is the actual coordinate range of the window according to the basic information, and performing projection transformation to obtain the Gauss-Kriging projection coordinate range; The tile level is calculated according to the display ratio of the map view window, and the tile row and column number range is calculated in combination with the Gauss-Kriging projection coordinate range; the formula for calculating the tile row and column number of the coordinate point (x, y) is: TileX=floor(originX-x) / (tileSize*resolution) TileY=floor(originY-y) / (tileSize*resolution) Among them, (originX, originY) is the origin coordinate of the base map data segmentation, tileSize is the tile size information tileSize of the base map, and resolution is the resolution information corresponding to each tile level; Arrange the tile row and column numbers, levels and sheet numbers according to the service's established format and initiate a tile download request; Get the tile data returned by the download request, calculate the Gauss-Kriging coordinate range of the tile based on the tile row and column numbers, and use the Gauss-Kriging projection coordinate range formula to calculate the Gauss-Kriging coordinate range of the tile, render it within the specified range of the map view, and visualize it on the mobile terminal.

2. The regional geological survey background map service application method based on the survey coordinate system according to claim 1 is characterized in that: The S1 specifically includes: Extract the map metadata file and image metadata file based on the uploaded base map file; Extracting associated information from the map metadata file and the image metadata file; The extracted associated information and base map files are stored in the corresponding databases respectively.

3. The regional geological survey background map service application method based on the survey coordinate system according to claim 2 is characterized in that: The S1 step further includes: Data asynchronous processing: confirm the data source storage address, call the base map file storage interface, push the message to the storage message queue, and use the message queue monitoring method to perform asynchronous processing; Data verification and identification: According to the data source storage address, check whether there is a file under the address; if there is a file, traverse the map data folder, identify the data file type according to the file name, and classify the data.

4. The regional geological survey background map service application method based on the survey coordinate system according to claim 2 is characterized in that: The base map file is stored in the MinIO database, and the associated information is stored in the PostgreSQL database.

5. The regional geological survey background map service application method based on the survey coordinate system according to claim 4 is characterized in that: The S2 includes: According to the associated information, the storage location information of the corresponding base map file is extracted from the PostgreSQL database, and according to the storage location information of the base map file, the base map file to be published is extracted from MinIO.

6. The regional geological survey background map service application method based on the survey coordinate system according to claim 1 is characterized in that: The S2 includes: before segmentation, traversing the base map file to determine its data type; If it is shp data, the coordinate origin and other information are extracted according to the map sheet number, and then the shp data is segmented; if it is DGSS vector data, the coordinate origin and other information are extracted according to the map sheet number, and the vector data is converted into MapGIS data format, and then the vector data is segmented; if it is image data, the coordinate origin and other information are extracted according to the map sheet number, and then the image data is segmented.

7. The regional geological survey background map service application method based on the survey coordinate system according to claim 1 is characterized in that: The S2 includes: after the segmentation is completed, calling the corresponding data publishing interface according to the data type to publish the data, and judging whether the publishing is successful; If the release is successful, the data is traversed to obtain the URL address of the tile and the base64 data stream of the tile, and the data preview information is stored in PostgreSQL. At the same time, the data release status of the file directory information and metadata information associated with the data release is updated, and finally the data release log is recorded; If the release is not successful, the data release log is recorded directly.

Images